The Impact of Trich Extends Beyond Lost Pregnancies
Trichomoniasis, more commonly known as “trich,” is a highly contagious venereal disease that can wreck a herd’s reproductive efficiency. A sound preventive program will help avoid abortions and ongoing losses at a time when every calf is vital to the bottom line.
“Preventing trich is one of the best ways to protect profits,” said Eric Metteauer, DVM, a veterinarian in Beaumont, Texas. When Dr. Metteauer moved to southeast Texas in 2013, numerous herds in his client base were infected with trich. Now, with intense management, he hasn’t had a bull test positive in two years.
“Trich can be devastating from an economic standpoint because of the high calf-crop losses,” said John Davidson, DVM, senior associate director of beef cattle professional services, Boehringer Ingelheim. He has seen decreased calf crops in trich-infected herds of up to 50 percent.
“The economic impact of this venereal disease in a cow herd is felt through lower weaning weights due to delayed breeding, testing of potentially infected bulls, and replacement of infected cattle,” Dr. Davidson added. “Beyond replacing cattle, ongoing surveillance to ensure the herd is trich-free plus vaccination of the herd cost money, too.”
“The first trich-infected herd I dealt with had 36 of 50 bulls test positive,” noted Dr. Metteauer, who provides service to beef herds in a 100-mile radius of his clinic, ranging from 20-cow herds to 8,000-cow herds. “We’ve seen trich in a wide array of herds with all kinds of management practices.”
When herds have problems with conception rates and lower pregnancy rates, trich is often the diagnosis, but testing must be done to confirm. “If pregnancy rates are reduced by a large amount, we want to palpate the cows and determine if they have had long-term damage to their reproductive tract, or if they are carrying mummified fetuses,” Dr. Metteauer explained. “If this is the case, then we have to attack trich from the cow side and not just the bull side.”
“The trich vaccine can help cows fight the disease and save a pregnancy with proper timing, although pregnancy is not a determining factor for infection in all cows,” said Dr. Davidson. “The vaccine has been proven to reduce the shedding of Tritrichomonas foetus, the disease-causing organism, thereby helping to reduce the spread of the infection throughout the herd.”
When the vaccine is given the first time, Dr. Davidson stresses the importance of giving a booster two to four weeks following the first dose. The second dose needs to be given 30 days prior to breeding season. This helps exposed animals fight the organism causing the disease. Cattle that have previously been vaccinated only require one dose.
“The problem with trich is there is no legal treatment in food animals,” Dr. Davidson asserted. “Bulls become permanently infected and need to be disposed of properly. While cows can develop an immune response to the disease, about 5 percent are permanently infected, and the others often don’t have a viable pregnancy.”
He continued, “Leased bulls can be a problem as they are often not tested in between movement of cow groups. I recommend that a 30-day trich test be done on all bulls prior to turnout.” When a herd tests positive and some bulls test negative, he said it is important to retest the negatives two weeks later to ensure their status.